Plz solve this

Plz solve this What is the slope of the tangent line drawn to the hyperbola xy = O) at point (a, 1) (b) —lla

Differentiate the eqn of curve w.r.t. x. It will give the slope of tangent on the curve at any point
i.e. x (dy/dx) + y = 0 
=> dy/dx = -y/x
Hence, slope at point (a,1) is (dy/dx) = (-1)/(a) = -1/a

Ans is option B.